Improvement in screw-swaging machines



M. D. LTJEHRS. SGBEW-SW'AGING MACHINES.

No. 194,875. Patented Sept. 4,1877.

WITNESSES I, INVENT 7 1482315 7 q i -gg NIT STATES PATENT e em MICHEL D. tonnes, or emtttxm, IoHio. I H

IMPROVEMENT m S'CREW-SWAGING MACHINES.

Specification forming part of Letters Patent No. 194,875, dated September 4, 1877 application filed April 27, 1877.

To all whom it may concern Be it known that I, MICHEL D. LUEHRs, of Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Machinery for Rolling Threads upon Bolts, &c.; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying-drawings, which form part of this specification.

y invention relates to machinery for rolling threads upon bolts, set-screws, &c.; and consists in two surfaces or beds with parallel grooves in each bed, between which the bolt is rolled by the relative movement of one bed over the other, whereby the grooves impress the threads upon the interposed bolts, in combination with friction-rollers supporting the said beds, and receiving the strain imposed upon them.

In the drawings, Figure 1 is a view in elevation of a machine embodying my invention. Fig. 2 are plan views of the working faces of the two grooved plates.

the bolt constantly between the abutments c friction-rollers A, and the plates are thereb,

firmly held at their work. The plate B s00 passes so far as to permit the bolt to dro;

down complete. Itis'apparent that if the bol be inserted between the plates, and it is one. grasped by the grooves, it can no longer drav out longitudinally. For this reason the bol should be of such a size that it shall not quit fill the space between the threads of the lowei plate and the threads of the upper plate, sc that when the grooves act upon it there may be some space left into which the metal displayed can expand.

In order to insure a bolt of the proper relative size, I preferto form the portions 11 of the plates smooth, the office of these smooth portions being to roll the bolt down to the proper diameter if it should happen to vary therefrom. The construction of these plates tively to the bolt is indicated more clearly in the sectional views in Fig. 1.

In order to adapt the machine to roll threads upon different sizes of bolts, one oftheplatesas, for instance, Band the adjacent friction- A is any suitable frame-work. B B are roller should be made vertically adjustable. the two grooved plates attached,respectively, Such adjusting mechanism may be of any to the connection-rods O O, which terminate suitable nature, and forms no part of my inin yokes D D, which are driven in opposite vention but the mechanism shown at H and directions by the cams E E on the drive- I is an example; but it may be accomplished shaft F. without these adjustments by making sepa- A are friction-rollers, so located as to rerate dies to be inserted upon the plates B B, ceive and support the strain upon the plates and making these dies of the proper thickness B B. The plates B B are grooved, respectto correspond with the given diameter of the ively, with grooves b 12 These grooves are bolt to beinsertedbetween them, substantially given an angle to thelineof directionin which as shown in the separate view at the right in the plates move corresponding to the desired Fig. 1. It should also be understood that the pitch to be given to the thread. invention should be limited to no particular The operation of the device is as follows: means for driving the plates B B, but that The plates being in the position shown in any suitable mechanism may be employed, Fig. 1, the bolt is inserted, as there shown at the yokes l) D and the cams E E being emit is immediately grasped between the ployed simply to demonstrate the invention. plates B B, and as the plate B is moved in It is also apparent that one of the plates may one direction while the plate B is moved in be stationary, and the threads be formed by the opposite direction, the bolt is rolled subsliding the other plate over it upon the interstantially about its own axis, and the plates posed bolt. impress the threads upon the bolt by means For larger threads, or for threads with a of the grooves b 12 greater pitch, there should be provided plates It will be seen that this construction holds or grooved working-faces, the grooves of which with their grooves and smooth portions rela- (1 correspond with the size of the thread he desired pitch, and these may be in- [06d in place of the plates B B in any ble manner.

hat I claim is .e grooved plates A B, made with the th surfaces b the same constituting 55 having respective flat portions adapted vll the bar to an exact proper diameter, having a portion of each groove extendpartly above and partly below these flat whereby the parts of the bar grasped are expanded substantially surfaces, between the projections or ribs into the bottoms of the grooves,

as set forth.

whereof I have signed my In testimony name to this specification in the presence of two subscribing witnesses.

MICHEL D. LUEHRS. Witnesses: FRANCIS TOUMEY, W. E. DONNELLY. 

